Turbocharge yields with nitrogen-fungicide synergy

Combine foliar applications to help fight stress, promote plant growth.

WRITTEN BY JASON WORTHINGTON, MFA SENIOR STAFF AGRONOMIST

Turbocharged engines are popular in many vehicles today because of the improved performance they provide. The turbocharger boosts horsepower, or output, while increasing fuel efficiency. It works by capturing unused energy from the engine exhaust to power a turbine. This, in turn, powers a compressor, which forces air into the intake of the vehicle, allowing a greater percentage of fuel to burn with each stroke of the engine. The result is greater output with less fuel by introducing a little more air.

The turbocharger is a really good example of synergy, where the output seems to outpace the cost of the inputs. Synergies in crop inputs are often misunderstood, oversold or dismissed, but some combinations do work and pay big dividends. One such example of successful synergy is the use of foliar slow- release nitrogen (SRN) in conjunction with foliar-applied fungicides.

Slow-release nitrogen products are often touted as a more efficient method of N delivery in which low-use rates can replace multiple pounds of soil-applied N to reach a similar yield. In my opinion, this is the worst expectation to have from an SRN. It can’t replace sound base nitrogen fertility—just like a turbo would be useless if there were no oxygen to pump into the system. 

Where slow-release nitrogen can really shine is when used with strobilurin fungicides. Beyond disease control, fungicide benefits include stay-green, stress tolerance and standability. What we don’t often discuss is where those advantages come from. With stress tolerance, increased photosynthesis and grain fill, the biggest impact comes from increased efficiency in nitrogen metabolism. The trick is having enough available N to “boost” that process. Like the turbocharger increases the amount of oxygen for an engine to more efficiently burn fuel, SRNs provide enough nitrogen to allow fungicides to reduce stress and promote plant growth, resulting in more gain at higher N efficiency.

We’ve seen positive results of an SRN-fungicide combination in trials like the one conducted by Dr. Kelly Nelson with the University of Missouri’s Greenley Research Sta- tion. He added 1 gallon of SRN to a fungicide application of Headline AMP at tassel to corn. While Head- line alone added 14.5 bushels per acre, adding SRN led to an increase of more than 25 bushels per acre. Thanks to the synergy created by the combined application, the amount of N is far less than required to add 9 bushels in traditional thinking.

Slow-release nitrogen products have been available for quite some time, and we have recommended them as a way to increase the efficiency of a fungicide application. Recently, MFA took it a step further by introducing a new proprietary product, Gold Advantage Trend-B, which is an SRN with boron added. Boron is an essential nutrient needed during the crop’s reproductive stages for grain development.

The issue with boron, unlike many plant nutrients, is that it is very mobile in the soil but not in the plant. This means that even if you do fertilize with boron up front, what is not taken up early is likely lost, and what is taken up early does not move in the plant to areas it is most needed. A plant with a fungicide plus SRN and deficient boron is like a turbo’s boost being held back by an engine with poor timing. Trend-B not only adds the small amount of available N necessary to help a fungicide “turbocharge” plant performance, but it also helps maintain optimal boron nutrition, which is often needed late in the season.

Proper timing is critical to get the most out of these applications. Talk with your Crop-Trak consultant or other experts at your MFA location today about the opportunity to improve your crop’s health and increase yields by combining fungicides with SRN foliar nutrition.

Written by Jason Worthington, MFA senior staff agronomist for the June/July issue of Today's Farmer Magazine.